Oil and chip separator



March 24, 1959 F. A. ZIHERL 2,378,943

I on. AND CHIP SEPARATOR Filed April 20, 1955 INVENTOR. FRANK A. ZIHERL BY Y A TToRNEis x 2378,94: I on. AND cmr SEPARATOR Application April 20,1955, Serial No. 502,631

8 Claims. (Cl. 210374) This invention, in general, relates to improvements in the centrifuge art, and; in:particular, to improvements in centrifuges adapted to separate liquids from, solids.

An illustrative example of one need for eificient separation of liquids-from solids is the reclamation of industrial cutting oils, and. the like, from metal chips, shavings, and so forth, which are produced in great volume in present dayhigh production industrial turning operations.

A common method in present use for reclaiming oil from oil laden chips and shavings is to place the oilsoakedchips in a largebasket from about founto five feet in diameter. and approximately threefeet deep, and then to place the basket in a bucket for rotation therein. The oil is separated by centrifugal force from the metal shavings and chips, and is collected in the bucket for further disposal. After an optimum of oil has been recovered from thechips, the basket is then removed from the bucket and the chipsare dumped into a shop truck, conveyor or the like for subsequentdisposal. The size of this basket is such that it normally requires an overhead crane of some denomination to hoist the basket into the drum and to remove it after the oil recovery op eration has been completed.

Objections to this system reside inthe fact that an inordinate amount of time is necessarily consumed in loading and unloading the basket, and otherwise handling and rehandling the chips. A further objection to this system is that the operation is not adapted to be made continuous since the machine can only operate on one batch of chips at a time. A still further objection to this system is the fact that, in. a busy shop, it requires the attention of at least one. man full-time, and finally it has been a matter 'of experience that the saving in reclaimed oil barelyjustifies the expense of running the operation. Shops too small to be equipped with centrifugal-type drums, as described hereinabove, or' shops which have abandoned the above basket and drum oil separation operation for the reasons [set forth above, sometimes make an effort to reclaim somejoil by merely allowing an accumulation of chips todrain over a period of time into a recovery pit or the like. Although this system is not as costly, space providing, it is much slower than the present centrifuge operation aridnot nearly as eflicient. It is, therefore, anobject ofthe present invention'fto provide an improved centrifuge which may be operated continuously and'efliciently with a minimum of supervision and manual attention. I

Other objects of the invention include the provision of 'a novel centrifuge which can be continuously conveyor loaded and uiiloadedfa novel centrifuge which is a fraction of the sizeof present oil recovery-centrifuges and yetwhich-is at leastof 'equal capacity;the provision of a novel centrifuge having a feed screw rotatably mounted xwithin acentrifuge bucket or drum into which solid matter is charged and :passed from end to end while liquids are centrifugally forced from the solid material and collected adjacent theperiphery of the centrifuge bucket;

2,878,943 Patented Mar. 24, 1959 and the provision of a novel centrifuge having a centrifuge bucket and a feed screw axially rotatable therein which are differentially rotated at predetermined angular velocities in the same angular direction, the differential in angular velocity between the feed screw and the bucket causing the solid matter to be fed from one end of'the bucket to the other.

To the accomplishment of the foregoing and related ends, said invention then consists of means hereinafter fully described and particularly pointed out in the claims, the annexed drawings and the following description setting forth in detail certain structure embodying theinvention, such disclosed means constituting, however, but one of various forms in which the principle of the invention may be used.

Figure 1 is an elevational view ofa preferred embodiment of the invention with parts insection to more clear ly show their relationship with respect to the other parts of the mechanism.

. The preferred embodiment of the invention is a continuous-operation centrifuge into which liquid laden or soaked solid matter is continuously charged by conveyor means or the like into one end and, as the solid matter is slowly fed from one end of the centrifuge to the other,

the liquid is forced from this matter by centrifugal force.

made of. structural members, suitable sheathing 16 enclosing the side and top portions of the frame, and a solid matter inlet funnel -18 passing through the top end 20 of the housing, the lower end 22 of which is positioned over the top of a centrifuge bucket 24. An inlet funnel material conveyor 26 is positioned adjacent one edge of the funnel to continuously transport material. to be charged into the funnel. This conveyor is preferably of the screw feed type, but under certain circumstances it is contemplated thata belt conveyor or the like may be employed.

.A shaft .2 8 is journaled in the frame to rotate about a vertical axis 30. The upper end of the shaft 28 is centered in the housing 12 for rotation therein by means of an anti-friction bearing 32. The lower end of the shaft is supported for rotation in an anti-friction thrust bearing 34 which is contained in a bearing housing 36. The bearing housing 36 is integrally secured by means of a spider 38, of whichit is the hub, to frame angle iron members 40 and 42. Because the lower end 22 of the inlet funnel 18 is positioned concentrically with the centrifuge bucket 24, the shaft 28 which is also concentric with the bucket must necessarily pass through the inlet funnel wall44. A feed screw mounting sleeve 46 is rigidly secured to the lower end of the shaft 28 to carry a feed screw'48 integrally thereon. The flights 50, 52, and 54 of the feed screw are securedto the sleeve 46 by means of a pl'urality of ribs 58 radially extending between the sleeve 46 and the feed screw 48. The upper flight 56 of the feed screw 48 is supported by a plurality of ribs 60 which are integrally fastened between a chip deflector platform 62 and feed screw flight 56. The chip deflectorplab form 62 is positioned immediately beneath the lower end dropped through the funnel into the bucket 24.

A pair of anti-friction thrust bearings 64 and 66 are. secured to the shaft 28 adjacent opposite ends of the sleeve 46. The upper bearings 66 are adapted to support rotatably thereon a bucket support sleeve 68' which fits concentrically about the upper portion of the shaft 28, and the lower bearings 64 are secured within a bearing shield or housing 70 which also serves as the hub of aspider 72 secured to the lower rim 74 of the bucket 24. Abearing housing 76, which encases the bearing66, is rigidly secured to the lower end of the bucket support sleeve 68 and serves as the hub of a bucket supporting spider 78. The spider 78 is rigidly connected between the bearing housing 76 and an annular ring 80 which. surrounds the lower end 22 of the inlet funnel 18.. It will be noted that the ring is provided with a conical inner wall. surface 81, which, because of its downwardly diverging form, guides material onto the deflector plate 62. The ring 80 is rigidly secured to a bucket lid 82,. which overlaps the upper rirn 84 of the bucket, andis provided with a central opening 86 to permit the inlet funnel 18 to pass therethrough. The bucket lid 82 is spaced apart from the upper rim 84 of the bucket 24 to provide escape ports as at 88 to enable fluid to be. centrifugally forced therethrough into an oil collector pan 90, positioned about the periphery of the bucket.

A sheave bearing support or flange 92 is rigidly secured to the bucket support sleeve 68 and carries thereon ananti-friction bearing 94 to which is secured a sleeve motor'sheave 96. Theouter race 98 of bearing 94 is securedto flange 92, and the inner race 100 rests on a shoulder 102 of the shaft 28. A spacer sleeve 104 rests on the inner race 100 of the bearing 94 to support a shaft motor sheave 106 which is rigidly secured to the upper. end of the shaft 28. It will be noted that the diameters of the sleeve and shaft motor sheaves 96 and 106 respectively are differential with respect to each other, and either the sleeve 68 or the shaft 28 may have the larger sheave secured thereto depending on the direction of angular rotation provided by the drive motor 107. It will be noted that timing belt drives 109 and 111 are usedto connect the motor pulleys 113 and 115 to their respective sheaves 96 and 106. These timing belt drives are flexible composition belts having molded teeth which mesh with the teeth of the pulleys and sheaves. In this way a constant differential between the speeds of rotation of'the bucket 24 and the feed screw 48 is'maintained, and this'dilferential will not vary due to belt wear, slippage and the like.

The end result desired is to rotate the feed screw 48 and bucket 24 differentially so as to force solid material from the top end 108 of the bucket out through the lower open end or bottom 110. To this end, if the feed screw and bucket are rotated clockwise in the direction indicated by arrow A, then the feed screw 48 must rotate slightly faster than the bucket 24 in order to impart any downward movement to the material in contact with the feed screw blade. Accordingly, in this instance, the shaft 28 will be driven by the smaller diameter motor sheave 106. On the other hand, if the directionof rotation of the feed screw and the bucket is in the direction indicated by arrow B, then it is necessary that the bucket 24 rotate slightly faster than the feed screw 48 in order to accomplish the same result in downward movement of material within the bucket. In. this latter example, therefore, the bucket support sleeve 68 would be provided with the smaller diameter motor sheave 106. Whether it is the bucket or the feed screw which rotates faster is relative, and the mechanism will operate equally well in either direction.

Once the required angular velocity is determined which is necessary to centrifuge liquid from solid matter within the bucket 24, then the increment of angular velocity differential between thefeed screw and the bucket. is

determined so that the length-of the time it takes to feed material from the top 108 to the bottom of the bucket is sufiicient to extract an optimum amount of liquid from the solid material. In other words, by the time the solid matter has reached the open bottom 110 of the bucket 24, substantially all liquid should be extracted, whereinafter the material is then free to drop through the open. bottom of the bucket onto a material conveyor 114 which conveys the material away from the centrifuge for subsequent disposal. Like conveyor 26, conveyor 114 is preferably a screw feed type, but other types of conveyors may be satisfactory depending on circumstances. A chipguide118 comprises a cylindrical member fitting about the rim 74 of the lower end of the bucket, and is provided to direct chips downwardly onto the conveyor 114.

It will be noted that the bucket 24 is in the nature of an inverted frustum of a cone, having its inner wall portion 116 inclined from bottom to top outwardly. The periphery of the feed screw 48 is adapted to conform to the shape of the inner wheel of the bucket 24, and in the present instance, is substantially conical in form. The outer feed screw blade periphery 120 is radially spaced away from the inner wall- 116 of the bucket 24 to permit liquid to pass upwardly therebetween. The liquid, by virtue of the centrifugal force imparted to it, naturally follows the outward inclination of the inner bucket wall 116 until it meets the junction between the bucket lid 82 and bucket rim 84. Here again, space must be provided, as at 88 to permit the liquid to pass between the rim and the lid. The amount ofspace provided between the bucket 24 and the feed screw 48 and between the rim and the lid is a matter'of choice depending on the type of substance being separated, and, in somemeasure, dependent upon the type of solid from which the liquid substance is separated. When the centrifuge is employed to separate industrial oils from oil-soaked chips, and the like, the feed screw must be radially spaced from the inner wall' 116 of the bucket 24 a distance suflicient to permit the oil to pass thereby, but this distance must be such that chips cannot become wedged therebetween.

In summation, solid materials, such as oil-soaked chips, are transported on conveyor 26 into an inlet funnel 18 wherein they drop by gravity onto a deflector plate 62, and are deflected therefrom into the path of the upper flight 56 of the feed screw 48. Assuming the feed screw 48 and-bucket 24 to berotating in the direction of arrow A, then the feed screw will be rotated just an increment faster than the bucket in the same angular direction to feed the material downwardly'toward'the lower opening 110 of the bucket. The progress. of the material downwardly is relatively slow, and during which time the oil on the chips is centrifugally forced against the inner wall 116 of the bucket, and upwardly along the inner wall until meeting with the bucket lid 82,.whereinafter it'is directedthr'ough specially provided openings88 between the bucket and the bucket lid into an oil. collector pan 90, as aforesaid.

Assuming, for example, that the feed screw 48 rotates twelve revolutions a minute faster than the bucket 24, byvirtue of the differential in diameters of the sheaves 96 and 106, and further assuming, for example, that each flight of the feed screw 48 is spaced four inches apart from the next adjacent flight, each flight then. would make one revolution every five. seconds. relative. to the bucket 24, and would advance the material four inches each revolution. It would then require twenty seconds for the four flights of. the feed screw tomove the material from the top ofthe bucket to the discharge opening in the bottom, at which time. substantially all reclaimable oil should have been centrifugally removed from the chips.- Twelve revolutions per minute has been selected for. example only, since it is a matter of experience how much faster or slower than the bucket the feed screw will operate, and this will vary depending on the type of material passing through the centrifuge. Although reclamation of oil from oil-soaked chips has been used as a preferred example to explain the function and operation of the preferred embodiment of the centrifuge, it is to be understood that this invention is not to be limited to this specific application, but rather is intended to be employed for all suitable centrifuge operations involving liquids and solids.

It is to be further understood that while only one embodiment of the invention is shown herein, this embodiment is by way of example only and is not to be construed in a limiting sense. Other arrangements and modifications will occur to those skilled in the art and may be resorted to without departing from the scope of the invention.

I claim:

1. The improvement in an oil and scrap separator for separating cutting oils from metal scrap comprising: a frame; a shaft journaled in said frame to rotate about a vertical axis; a helical screw conveyor concentrically mounted on said shaft adjacent its lower end; a sleeve fitted concentrically about the upper end of said shaft to freely rotate thereabout; an open-ended bucket supported on said sleeve to encase said screw conveyor; means to differentially rotate said bucket with respect to said screw conveyor at predetermined angular velocities and in the same angular direction; and a chute secured to said frame and adapted to direct liquid-laden metal scrap into the top portion of said bucket, whereby metal scrap deposited in the top portion of said bucket is cleaned from the inner wall of the bucket and fed by means of a screw conveyor to the bottom of said bucket while the liquids on said metal scrap are centrifically separated therefrom and are centrifically forced into contact with the inner wall of said bucket.

2. The oil and chip separator set forth in claim 1, wherein the bottom of said bucket is open and obstructed to permit said screw conveyed metal scrap to drop freely therethrough.

3. The oil and chip separator set forth in claim 1, wherein said bucket is in the nature of an inverted frusto cone, whereby the interior wall of said bucket slopes upwardly and outwardly from the axis of rotation, and means adjacent the upper rim of said bucket at the locus of substantially greatest radius to collect centrifuged liquid therefrom.

4. The oil and chip separator set forth in claim 1, wherein the blade of said screw conveyor is radially spaced a predetermined distance from the inner wall of said bucket to permit centrifuged liquid to pass therebetween and to prevent metal scrap from wedging therebetween.

5. The oil and chip separator set forth in claim 1, wherein the bottom of said bucket is open to permit said screw conveyed metal scrap to drop therethrough; a spider secured to said frame to secure a shaft supporting journal concentric with the axis of rotation; a spider secured to the bottom rim of said bucket to support a shaft centering journal concentric with the axis of rotation; and a bucket supporting spider secured to the upper portion of said bucket and to a journal integral with the lower end of said sleeve, whereby said shaft and said bucket are concentrically aligned and rotatably supported by said spider journals in a fashion to present a minimum of obstruction to solids passing therethrough.

6. The centrifuge set forth in claim 1, the upper end of said bucket having a substantial opening, and including a platform rotatably secured to said shaft beneath said opening adapted to intercept liquid laden solids from said chute and to direct said solids radially into contact with said blades.

7. The centrifuge set forth in claim 1, including a second sleeve rigidly secured to the lower end of said shaft and adapted to rotatably support on its upper end said first mentioned sleeve.

8. The centrifuge set forth in claim 1, including a lid secured to the upper rim of said bucket and spaced vertically therefrom a predetermined distance to permit centrifuged liquid to pass therebetween and to trap metal scrap from passing thcrebetween; and means to collect fluid passing from said bucket.

References Cited in the file of this patent UNITED STATES PATENTS 136,485 Burchardt Mar. 4, I873 726,696 Kasson Apr. 28, 1903 775,320 Van Kirk Nov. 22, 1904 924,376 Phillips June 8, 1909 1,235,193 Elmore July 31, 1917 1,699,471 Laughlin June 15, 1929 2,129,992 De Mattia Sept. 13, 1938 2,292,990 Chatain Aug. H, 1942 FOREIGN PATENTS 6,448 Great Britain of 1909 217,264 Great Britain June 19, 1924 297,914 Great Britain Oct. 4, 1928 449,616 France Dec. 28, 1912 

